Exhaust gas recirculation (EGR) devices, which recirculate a portion of exhaust gas to an intake passage for an internal combustion engine including a supercharger, are known. Among these EGR devices, a low pressure EGR device uses a cooler to cool a portion of relatively low pressure exhaust gas downstream of a turbine of the supercharger. Then, this low pressure EGR device recirculates the low pressure exhaust gas to the intake passage upstream of a compressor of the supercharger. As such, a large quantity of low temperature exhaust gas may be recirculated.
In internal combustion engines that include a low pressure EGR device, when water vapor in the exhaust gas is cooled by the cooler or the like, condensed water may form. In this case, there is a concern that the condensed water may corrode various devices. In this regard, JP 2012-163061 A describes a controller that estimates an accumulated amount of condensed water in a low pressure EGR passage. If this accumulated amount exceeds a reference amount, the controller decreases the recirculation amount of low pressure exhaust gas, and increases the recirculation amount of high pressure exhaust gas. As a result, accumulation of the condensed water may be suppressed from exceeding the reference amount.